Decomposition rates of methyl tert-butyl ether and its by-products by the Fenton system in saline wastewaters

• Published in: Separation and purification technology Vol. 52; no. 2; pp. 317 - 324
• Main Authors: Siedlecka, E.M., Stepnowski, P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2006; Elsevier Science
• Subjects: Advanced oxidation processes (AOPs); Applied sciences; Chemical engineering; Exact sciences and technology; Fenton reaction; General purification processes; Hydrogen peroxide; MTBE; Oxidation; Pollution; Reactors; Salinity; Wastewaters; Water treatment and pollution; FID; TBA; Hydrogen peroxide; MA; Advanced oxidation processes (AOPs); TBF; Fenton reaction; Oxidation; DO; MTBE; AOPs; Salinity; Complexation; Intermediate product; Reaction product; Operating conditions; Waste water; Kinetics; Rate constant; Waste water purification; Degradation product
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2006.05.014

The primary aim of this study was to gain an understanding of how different concentrations of chloride ions affect the oxidation of methyl t-butyl ether (MTBE) in the Fenton system. Oxidation of MTBE in a chloride-free reaction mixture was rapid and very effective, but was inhibited even by the lowest chloride concentrations employed. After 90 min of reaction in the presence of 0.05–1 M of chloride ions, the effectiveness of MTBE degradation dropped to 97–68%, respectively. It was found that the inhibition of Fenton's reaction by chloride ions depends on two factors, thus, complexation and radical scavenging. Under the experimental conditions of the current study, comparison of rate constants for possible degradation reactions showed that most of the OH radicals formed by the reaction of H 2O 2 with Fe 2+ were consumed by Cl −. The influence of chloride ions on the degradation of four intermediate products in identical system was also studied: in chloride-free solution under the same experimental conditions, t-butyl alcohol (TBA) was the major by-product, followed by t-butyl formate (TBF) and acetone. In the process of degradation, the distribution of MTBE intermediates varied with the different chloride concentrations. Furthermore, by varying the concentrations of Fe 2+ and H 2O 2, it was possible to track the behavior of MTBE degradation products in the Fenton system in order to find optimal conditions for saline wastewater treatment.